Commit 33a9c41b authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Russell King
Browse files

ARM: 6255/1: Workaround infinity loop in handling of translation faults 



On ARM one Linux PGD entry contains two hardware entries (see page
tables layout in pgtable.h). We normally guarantee that we always
fill both L1 entries. But create_mapping() doesn't follow the rule.
It can create inidividual L1 entries, so here we have to call
pmd_none() check in do_translation_fault() for the entry really
corresponded to address, not for the first of pair.

Signed-off-by: default avatarKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 6338a6aa

arch/arm/mm/fault.c

+10 −1
Original line number Diff line number Diff line
@@ -413,7 +413,16 @@ do_translation_fault(unsigned long addr, unsigned int fsr, 
	pmd_k = pmd_offset(pgd_k, addr);

	pmd   = pmd_offset(pgd, addr);



	if (pmd_none(*pmd_k))

	/*

	 * On ARM one Linux PGD entry contains two hardware entries (see page

	 * tables layout in pgtable.h). We normally guarantee that we always

	 * fill both L1 entries. But create_mapping() doesn't follow the rule.

	 * It can create inidividual L1 entries, so here we have to call

	 * pmd_none() check for the entry really corresponded to address, not

	 * for the first of pair.

	 */

	index = (addr >> SECTION_SHIFT) & 1;

	if (pmd_none(pmd_k[index]))

		goto bad_area;



	copy_pmd(pmd, pmd_k);